The medications used for this study include: C-peptide. This is a synthetic product (not from human or animal sources) that is man-made and identical to the C-peptide made by the body. C-peptide is made at the same time as insulin, one molecule of insulin equals one molecule C-peptide. By giving C-peptide that is synthetic, researchers can measure how the C-peptide breaks down in the body, which could then be related to how insulin breaks down in the body. Somatostatin will also be used during the same test as the C-peptide. While receiving Somatostatin, the production of insulin by the patient will be stopped. This medication will only be given for 4 hours and the blood sugar will be monitored during the entire procedure. Insulin & Glucose will also be given by IV during certain tests to regulate the blood sugar. Blood sugars will be maintained within a certain level and this will be achieved through the administration of insulin and/or glucose. The patient's blood sugar will be monitored at frequent intervals throughout the various procedures.